Circuit-closing device.



PATENTED JUNE 28, 1904.

. A. B. CHANCE.

CIRCUIT CLOSING DEVICE. nnmumn rum) APB. e, 1903.

H0 IODEL.

I flax/(1J5. C/iamca c jvwem roz Tm mums PETERS ca. momu nu Patented(Tune 28, 1904.

PATENT OFFICE.

ALBERT BISHOP CHANCE, OF CENTRALIA, MISSOURI.

CIRCUIT-CLOSING DEVICE.

SPECIFICATION forming part of Letters Patent N 0. 763,464, dated June28, 1904:, Application filed'hpril G, 1903. Serial No. 151,367. NOodel.)

To all whom it may concern.-

Be it known that I, ALBERT BISHOP CHANCE, a citizen of the UnitedStates, residing at Centralia, in the county of Boone and State ofMissouri, have invented certain new and useful Improvements inCircuit-Closing Devices; and I do declare-the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention is an improved circuit-closing device for telephonesystems, by means of which the receiver-hook is adapted to be operatedto call central for a connection and for automatically throwing the dropor annunciator at the central office to secure a positive ring off whenthe receiver is hung thereon.

My invention consists in the construction, combination, and arrangementof devices hereinafter described and claimed.

In the accompanying drawings, Figure 1 is an elevation, partly insection, of a circuitclosing or switch device embodying my invention.Fig. 2 is a detail view, on an enlarged scale, of one of thecontact-pieces.

The telephone switch-hook P is provided with an obliquely-disposedconducting-cam G, and the switch-spring E has a similarly-disposedconducting-cam H,insulated on its lower side, as at I. A suitable springa is provided for the switch-hook to raise the latter.

The switch-spring or switch-spring arm E is disposed substantially atright angles to the switch-hook, extends across one side thereof, andits obliquely-disposed contact-cam I is in the path of the switch-hookcontact-cam G. The free end of the switch-spring arm extends beyond itscontact-cam.

A spring L, which serves to prevent casual vibration of theswitch-spring, engages the latter at its extended free end, asshown.

By the provision of the extended free end of the switch-spring armextending beyond its contacting point and of the spring L bearingagainst said end of the switch-spring arm, the operation of the deviceis rendered very much more certain than would otherwise be the case, andthe springs employed may be of comparatively slight strength, so as notto interfere with the operation of the switchhook.

WVhen the receiver is removed from the switch-hook, the latter movesupwardly under the impulse of its spring a, and its conducting-cam Grengages and passes the insulated side of the cam H, fastened on theswitchspring E, so that no current passes, because electrical contact isnot established.

A signal to central for a connection may be made by removing thereceiver, allowing the switch-hook to move upwardly, then depressing theswitch-hook and releasing the same. When the switch-hook is depressed,its cam G engages the metallic conducting side of the cam H of thebattery switch-spring E, thereby establishing momentarily abattery-circuit through the line and the annunciator at central to causethe drop to be released. By the provision of the insulator on one sideof the contact-cam of the battery switch-spring E a signal to central todisconnect is prevented, as will be understood. A signal to central todisconnect is transmitted by the next descent of the switch-hook whenthe receiving-telephone of the subscriber is hung thereon.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

In combination with a movable switch-hook having an obliquely-disposedcontact-cam projecting from one side thereof, a switch-spring armdisposed substantially at right angles to the switch-hook extendingacross one side thereof having an obliquely-disposed contactcaminsulated on one of its contact sides projecting therefrom and in thepath of the switchhook contact-cam, the free end of such switchspringarm extending beyond its contact-cam and a spring to prevent casualvibration of the switch-spring and engaging the latter at its extendedfree end.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

ALBERT BISHOP CHANGE. Witnesses:

HORACE OHANsLoR GANo, FRANCES CHANCE.

